The following information was published in the May 1990
Field and Stream.  The article is titled "Stockton, Revisited".

The data is from a Report to the California Attorney General,
dated October 1989, and was prepared by Nelson Kempsky, Chief
Deputy Attorney General of the State of California.

Patrick Purdy's Rap Sheet:

April 1977: Listed as suspect in an assault
December 1978: Arrested for possession of stolen property and dangerous weapons.
March 1979: Arrested for possession of a dangerous weapon.
July 1979: Arrested for extortion and possession of a dangerous weapon.
August 1979: Accepted for treatment for alcoholism, and described as "very
     drug oriented."
August 1980: Arrested and convicted for prostitution.
August 1982: Arrested for cultivation of marijuana, and possession of
     marijuana for sale. Convicted in March 1983.
October 1982: Arrested for vandalism.
February 10, 1983: Arrested for public drunkenness.
February 13, 1983: Arrested for possession of a dangerous weapon.
July 1983: Purdy's application for a Security Guard Permit is received and
     processed by the State Bureau of Collections and Investigative
     Services.
September 1983: Listed as a suspect in a vandalism. No charges filed for lack
     of evidence.
October 1983: Licensed as a Security Guard by State Bureau of Collections and
     Investigative Services. Sunsequently hired and fired by three security
     services.
April 1984: Purdy buys Excam Targa .25 caliber pistol #MI13107 in Los Angeles.
October 1984: Arrested for attempted robbery; convicted of being an accessory
     to a felony.
November 1984: Diagnosed as suffering from substance induced personality
     disorder. Determined to be disabled because of this; declared eligible for
     Social Security disability payments.
July 1986: Buys a Davis .22 pistol, #79709 in Modesto, California.
October 1986: Buys a Browning Hi-Power 9mm pistol, #2CH1095 in Sacremento,
     California.
April 1987: Arrested for firing a gun in El Dorado National Forest. Charged
     with vandalism, resisting arrest, and assault on a peace officer. Attempts
     suicide in El Dorado County jail. Is diagnosed as suicidal and homicidal
     while at that facility. Is sent to Placerville Psychiatric Health Facility
     for further evaluation. Id diagnosed as "extremely dangerous," and
     deemed competent to stand trial. Is convicted of a misdemeanor; all
     other charges dismissed. Sentenced to 45 days in jail and three years'
     summary probation.
August 1987: Diagnosed by Social Security Administration report as "getting
     worse as time goes by."
August 1987: Buys an Ingram MAC-10 9mm pistol, #S7095032 in Stockton.
June 1988: Social Security reviews Purdy's disability claim, determines that
     he is still suffering from drug and alcohol abuse. refers him to
     treatment center.
August 1988: Buys Norinco 56S 7.62x39mm semiautomatic rifle #MS010963 in
     Sandy, Oregon.
December 1988: Buys Taurus 9mm pistol #TH141825 at a gun store in Stockton,
     after passing California's mandatory fifteen day waiting period and
     security check.
January 1989: Commits murders at Cleveland School, then takes his life.

Note that California had a mandatory 15 day waiting period for all handgun
purchases, Purdy bought 5 handguns, the last specifically mentions passing
the security check. The writer of the article assumes that since the other
four were also bought over the counter, that Purdy passed the check four
other times, although not specifically mentioned.