The answer to your question is a complex and interesting one. In July 1969 a music teacher named Gary Hinman was murdered in LA. He was killed by a member of the Manson family named Bobby Beausoleil. Susan Atkins participated in the killing. On the wall of Hinman’s house, Beausoleil made a paw print using Gary’s blood and wrote the words “Political Piggy.” Bobby was quickly captured driving Hinman’s car and his prints matched the paw print at Gary’s residence. Investigators knew that Bobby was a member of the family. Then the Tate-Labianca homicides occurred. At the Tate residence, the phrase “Pig” appeared while at the Labianca home “Death to Pigs” was the term used. Like at Hinman’s place, blood was used to write them. The Hinman Investigators saw the link immediately… I mean who wouldn’t? Massive overkill of the victims phrases alluding to pigs written in blood at all three crime scenes… consequently, the Hinman investigators never believed the evidence pointed to the Black Panthers. Oddly the Tate investigators couldn’t see the link they were too busy pursuing the possibility of a drug deal gone bad because Jay Sebring, Voytek Frykowski and Abigail Folger were involved in drugs. Meanwhile, the lack of drugs at the Labianca house made the murders there appear unlinked to the Tate homicides…the cops thought the crime was a copycat or perhaps a mafia hit. So the answer to the question is no the police never believed the Black Panthers had anything to do with the homicides. The answer to the second question is also no the police did not immediately pursue the family… instead they chose to ignore the Hinman investigators’ lead that would have cracked the case. The Family was not linked to the crimes until Susan Atkins made a jail house confession in December 1969. Interestingly, these events have led many people to theorize that the Helter Skelter motive for the crimes is just BS. The motive was to secure Beausoleil’s release from prison by committing a series of copycat murders that would make him look innocent. Actually, I think that motive is quite plausible since the Tate-Labianca murders occurred after Bobby’s arrest.