Pauline's father was Christian H Grass of Sanger, California. She didn't quite make it to the age of 16. Her death certificate states as a cause of death.
"Gunshot wound in the head by party unknown with murderous intent".

The following was taken from the Reno Gazette:
SWEETHEARTS DEAD AT HANDS OF UNKNOWN
Fresno County Officials Are Puzzled Over Lack of Any Clue to Murderer

FRESNO, Cal., July 11. – No solution of a double murder at Sanger, eighteen miles from here, Sunday night, in which Pauline Grass, sixteen-year-old Sanger school girl, and Alex Winter, her twenty-one-year-old companion, are believed to have been slain by some rejected admirer of the slain girl, had been found up to a late hour today. All the friends of the girl have been questioned by the police without result.
Boy Slain, Too
The bodies of the youthful sweethearts were found Monday morning by a delivery boy. The girl was found lying face downward in a vineyard about forty feet from where stood the automobile belonging to Winter. His body was found huddled in the rear seat of the machine.
The first assumption, that Winter had murdered his sweetheart and then turned the gun on himself during a lover's quarrel, was swept aside when autopsy surgeons found two bullets in the dead youth's brain.
Alexa Scheidt, son of a rancher near here, was questioned yesterday by Sheriff Jones regarding a fight which is alleged to have taken place about 9:30 Sunday night in Sanger between a number of Italians.
Ranchers Say He Was Alone
Scheidt told the authorities that the fight was over a woman, but that he did not believe it had any connection with the double murder. The officers scout the theory that the rejected Italian may have come upon Winter and Miss Grass and in the darkness mistaken them for the woman who had rejected him.
Ranchers living in the neighborhood of the scene reported yesterday that they had noticed Winter seated in the back of his machine early Sunday night but that no woman or girl was with him at the time.
Searching For Small Car
Another report stated that neighbors had seen a small automobile parked near Winter's machine on the night of the murder. The police regarded this clue as significant and are making every attempt to locate the driver of a car. A coroner's jury yesterday returned a verdict of murder after hearing the evidence in the case.


From the Modesto Evening News:
MURDER CLUES FADE; FRESNO MYSTERY IS DEEPER
Sheriff Continues Search As Boys One by One Prove Innocence of Connection With Double Crime

FRESNO. July 13. Three of Sheriff Jones' promising clues to the murder of Pauline Grass and Alex Winter were explained away early today.
Two youths supposed to have owned a flashlight found near the girl's body produced their own flashlight. Likewise they satisfactorily explained their whereabouts on the night of the double murder.
Investigation of reports that a second car had been seen parked that night near where Winter was found dead in his machine also developed that the "mystery car" was on an entirely different road.
Jones, however, has not given up the search for the murderer and still hopes that school boy and school girl gossip will ultimately give him the real lead.
Seven youths have already been quizzed by Jones in connection with the slaying of the couple. An unexploded automatic pistol shell of ( two illegible words ) in Winters's car gave trace of such a gun in the community. Its owner said the gun had been stolen from his cash drawer about three months ago. He told the sheriff whom he suspected of the theft.
Time of the double killing has been established between 10:30 and 11 o'clock, Sunday night.


From the Woodland Daily Paper:
Fresno Boy, Girl Murder Baffling Police; School Friends Are Questioned
FRESNO, July 11. – Authorities today were questioning school friends for possible motives for the killing yesterday of 16-year-old Pauline Grass and Alex Winter, 21-year-old companion on a night motor trip whose bodies were found near a roadside two and a half miles from Sanger, 18 miles from here.
The girl had been shot through the back of the head and her body was found 49 feet from a parked automobile in which was huddled the dead body of Winter.
The authorities believe that the pair were trailed by an irate friend of the slain girl who shot Winter and then ended the life of the young girl as she was attempting to flee.
GIRL STRUGGLES
Two bullet wounds were found in the brain of Winter by doctors who later conducted an autopsy. Evidence of a struggle between the girl and her assailant, duringwhich the girl's clothing was torn and her body badly bruised, was discovered in the autopsy.
According to local authorities, the girl and Winter were seated in the back of the machine when the murderer crept upon them and shot Winter twice. The girl is then supposed to have jumped from the machine and fled into a nearby vineyard with the murderer in close pursuit.
The theory is advanced that after overtaking the fleeing girl the man fired at close range.
The authorities at first advanced the theory that Miss Grass was shot by Winter during a quarrel and the youth, after realizing what he had done, ended his own life.
GIRL'S FRIENDS QUIZZED
When it was found that two bullets had entered Winter's brain and that a diligent search of the ground surrounding the scene of the murder failed to uncover the death weapon, the authorities came to the conclusion that the pair had been the victims of a double murder.
In an effort to apprehend the alleged murderer the authorities are checking up on all friends of the young girl, who recently graduated from grammar school. It is thought possible that a close questioning of her friends and acquaintances will uncover some clue that will lead to the apprehension of the murderer.
The dead girl is the daughter of a Sanger grocery store proprietor and Winter recently went to Sanger from Fresno to work on his uncle's ranch. They were last seen as they left the store, presumable to go for an automobile ride.


Many thanks to Trisha for helping me with my research. Her page is here: Copy and paste into address bar.

http://www.findagrave.com/cgi-bin/fg.cgi?page=mr&GRid=26546340&MRid=46793585&