Tang Yongming, the man who stabbed two American tourists -- one fatally -- and a Chinese tour guide in downtown Beijing on Saturday before killing himself acted out of despair over personal failures, police said in Hangzhou on Sunday.

The 47-year-old Tang had lost all hope after a series of failures in his life and took his anger out on society, according to the police department in his hometown in Zhejiang Province.

It called Tang's case an "individual extreme activity".

The police said fingerprints and DNA tests had confirmed Tang's identity.

An investigation found that Tang used to work at a meter factory in Hangzhou but had resigned.

According to the police, Tang, after two failed marriages, pinned all his hopes on his 21-year-old son Tang Wenjun, who was detained for 10 days in May 2007 for fraud. In March this year, the junior Tang was fined 2,000 yuan (about 290 U.S. dollars) and sentenced to six months in prison with a one-year suspension for theft.

The elder Tang had no prior criminal record.

In 2006, he moved to a rented house and sold his apartment for 200,000 yuan, which, according to the police, was soon spent by his son.

Tang vacated that house on Aug. 1, saying he would move elsewhere to do business. He called his son about 5 p.m. that day, saying that he would return to Hangzhou only if his business was successful.

He told his son not to make trouble any more, the police said.

On Saturday, Tang stabbed two American tourists and a Chinese tour guide at a well-known tourist site in downtown Beijing, killing one of them -- a man -- and injuring the other two, both women.

Tang then killed himself by jumping from the 130-foot-high second story of the 13th-century Drum Tower, where the stabbing took place, according to the Beijing Municipal Government Information Office.

(Xinhua News Agency August 11, 2008)